Reproductive Medicine and Biology

, Volume 9, Issue 3, pp 169–172

Sex-discordant twins despite single embryo transfer: a report of two cases

  • Nobuo Sugawara
  • Hideyuki Fukuchi
  • Machiko Maeda
  • Rie Komaba
  • Yasuhisa Araki
Case Report


We report two extremely rare cases in which the patients delivered male and female infants that were dizygotic twins (DZT) despite single embryo transfer. Case 1: The patient was a 35-year-old woman with a 9-year history of unexplained infertility. In an oocyte retrieval cycle, one blastocyst was transferred; at 26 weeks of gestation, she delivered a 704-g female infant and a 420-g male infant by cesarean section. Because both infants were of extremely low birth weight, they were placed in the neonatal intensive care unit. Congenital anomalies were not found in either infant. Case 2: The patient was a 30-year-old woman with a 1-year history of infertility. Hysterosalpingogram revealed bilateral tubal occlusion. In a frozen/thawed cycle one blastocyst was transferred during her natural ovulation cycle. She achieved a pregnancy and delivered a 2,877-g female infant and a 2,544-g male infant at 36 weeks of gestation by cesarean section. The female infant was diagnosed with a neural tube defect. No congenital anomalies were detected in the male infant. We hypothesize that the DZTs might have been the result of concurrent embryo transfer and natural ovulation and intercourse.


ART Dizygotic twin (DZT) Monozygotic twin (MZT) Multiple gestation Single embryo transfer 


  1. 1.
    Bergh C. Single embryo transfer: a mini-review. Hum Reprod. 2005;20:323–7.CrossRefPubMedGoogle Scholar
  2. 2.
    Japan Society of Obstetrics and Gynecology. Notice of avoiding multiple pregnancies in ART. Jpn J Obstet Gynecol. 2008; 60: 1159 (in Japanese).Google Scholar
  3. 3.
    Sugawara N, Komaba R, Maeda M, Araki Y. The study for reducing multiple pregnancy rate by elective single embryo transfer. J Fert Imp (Tokyo). 2008;25:157–61 (in Japanese).Google Scholar
  4. 4.
    Schachter M, Raziel A, Friedler S, Strassburger D, Bern O, Ron-El R. Monozygotic twinning after assisted reproductive techniques: a phenomenon independent of micromanipulation. Hum Reprod. 2001;16:1264–9.CrossRefPubMedGoogle Scholar
  5. 5.
    Alikani M, Cekleniak NA, Walters E, Cohen J. Monozygotic twinning following assisted conception: an analysis of 81 consecutive cases. Hum Reprod. 2003;18:1937–43.CrossRefPubMedGoogle Scholar
  6. 6.
    Edwards RG, Mettler L, Walters DE. Identical twins and in vitro fertilization. J In Vitro Fert Embryo Transf. 1986;3:114–7.CrossRefPubMedGoogle Scholar
  7. 7.
    Papanikolaou EG, Camus M, Kolibianakis EM, Van Landuyt L, Van Steirteghem A, Devroey P. In vitro fertilization with single blastocyst-stage versus single cleavage-stage embryos. N Engl J Med. 2006;354:1139–46.CrossRefPubMedGoogle Scholar
  8. 8.
    Chow JS, Benson CB, Racowsky C, Doubilet PM, Ginsburg E. Frequency of a monochorionic pair in multiple gestations: relationship to mode of conception. J Ultrasound Med. 2001;20:757–60. quiz 761.PubMedGoogle Scholar
  9. 9.
    Schoolcraft WB, Gardner DK, Lane M, Schlenker T, Hamilton F, Meldrum DR. Blastocyst culture and transfer: analysis of results and parameters affecting outcome in two in vitro fertilization programs. Fertil Steril. 1999;7:604–9.CrossRefGoogle Scholar
  10. 10.
    Behr B, Fisch JD, Racowsky C, Miller K, Pool TB, Milki AA. Blastocyst-ET and monozygotic twinning. J Assist Reprod Genet. 2000;17:349–51.CrossRefPubMedGoogle Scholar
  11. 11.
    Peramo B, Ricciarelli E, Cuadros-Fernandez JM, Huguet E, Hernandez ER. Blastocyst transfer and monozygotic twinning. Fertil Steril. 1999;72:1116–7.CrossRefPubMedGoogle Scholar
  12. 12.
    Jain JK, Boostanfar R, Slater CC, Francis MM, Paulson RJ. Monozygotic twins and triplets in association with blastocyst transfer. J Assist Reprod Genet. 2004;21:103–7.CrossRefPubMedGoogle Scholar
  13. 13.
    da Costa AL, Abdelmassih S, de Oliveira FG, Abdelmassih V, Abdelmassih R, Nagy ZP, et al. Monozygotic twins and transfer at the blastocyst stage after ICSI. Hum Reprod. 2001;16:333–6.CrossRefGoogle Scholar
  14. 14.
    Milki AA, Jun SH, Hinckley MD, Behr B, Giudice LC, Westphal LM. Incidence of monozygotic twinning with blastocyst transfer compared to cleavage-stage transfer. Fertil Steril. 2003;79:503–6.CrossRefPubMedGoogle Scholar
  15. 15.
    Papanikolaou EG, D’haeseleer E, Verheyen G, van de Velde H, Camus M, van Steirteghem A, et al. Live birth rate is significantly higher after blastocyst transfer than after cleavage-stage embryo transfer when at least four embryos are available on day 3 of embryo culture. A randomized prospective study. Hum Reprod. 2005;20:3198–203.CrossRefPubMedGoogle Scholar
  16. 16.
    Sugawara N, Maeda M, Komaba R, Araki Y. The study of clinical assessment for elective single embryo transfer using new embryo’s Score. J Fert Imp (Tokyo). 2009;26:167–71 (in Japanese).Google Scholar
  17. 17.
    Sugawara N, Komaba R, Maeda M, Araki Y. Comparison of implantation, pregnancy and miscarriage rates by between transfer of 2 or 3 embryos at the early cleaved stage. J Fert Imp (Tokyo). 2006;23:234–8 (in Japanese).Google Scholar
  18. 18.
    Sadler TW (Yasuda M, Sawano J translators). Langman’s medical embryology, Tokyo: Medical Sciences International; 8 revised 8 edition; 2001, pp 141–148.Google Scholar
  19. 19.
    Zech NH, Wisser J, Natalucci G, Riegel M, Baumer A, Schinzel A. Monochorionic-diamniotic twins discordant in gender from a naturally conceived pregnancy through postzygotic sex chromosome loss in a 47, XXY zygote. Prenat Diagn. 2008;28:759–63.CrossRefPubMedGoogle Scholar
  20. 20.
    Jkemans Ei, Lintsen MJ, Hunault AM, Bouwmans CC, Hakkaart CA, Braat L, et al. Pregnancy chances on an IVF/ICSI waiting list: a national prospective cohort study. Hum Reprod. 2008;23:1627–32.CrossRefGoogle Scholar
  21. 21.
    Hall JG. Twinning. Lancet. 2003;362:735–43.CrossRefPubMedGoogle Scholar
  22. 22.
    Souter VL, Kapur RP, Nyholt DR, Skogerboe K, Myerson D, Ton CC, et al. A report of dizygous monochorionic twins. N Engl J Med. 2003;349:154–8.CrossRefPubMedGoogle Scholar
  23. 23.
    Mains L, Ryan G, Sparks A, Van Voorhis B. Sextuplets: an unusual complication of single embryo transfer. Fertil Steril. 2009;91:932.e1–2.CrossRefGoogle Scholar

Copyright information

© Japan Society for Reproductive Medicine 2010

Authors and Affiliations

  • Nobuo Sugawara
    • 1
  • Hideyuki Fukuchi
    • 2
  • Machiko Maeda
    • 1
  • Rie Komaba
    • 1
  • Yasuhisa Araki
    • 3
  1. 1.Iwaki Women’s ClinicIwakiJapan
  2. 2.Fukuchi Ladies’ ClinicHitachiJapan
  3. 3.The Institute for ARMTMaebashiJapan

Personalised recommendations